It is important to advertisers, content producers and broadcasters to be able to ascertain the scope and characteristics of TV viewership for their programs. However, the nature of TV viewership, where broadcast programs can be displayed to one or many viewers, and where viewers can come and go during a program, presents a challenge to the accurate measurement of such numbers and characteristics. TV viewership agencies have adopted a number of approaches to determine who is watching TV and what they are watching. For example, some agencies ask participants to complete logs or interact with electronic tools to document their viewing. However, even when viewers have agreed to log their viewing, or that their viewing activities can be monitored, it can still be difficult to accurately measure a program's viewership. For example, if an individual logs an entry indicating that he or she has started watching a particular TV program but then is quickly distracted to attend to something else, e.g., leaving the room to answer an hour-long phone call, the TV viewership survey agency would assume that the individual has watched the program based on the logged entry, which constitutes a false positive data sample. Similarly, another individual may spend an entire night watch many TV programs without generating a single entry indicating what he or she is watching. In this case, the TV viewership survey agency would never know which TV programs the individual watched that night due to the lack of log entries, which constitutes a false negative (i.e., missing a data sample).